Merge pull request #240 from maciejmrowiec/master

Update ChangeLog
Added AlpineLinux Flavour and Package Management (apk).
Fix iteration regression bug where embedded cf_null would not be skipped
Final changes to make apk work.
Acceptance tests for cf_null
Merge pull request #242 from markburgess/master

Regression bug reported on the help list. cf_null embedded in a list was not ignored.
Fix redefinition of FD_SETSIZE for CygWin. (Redmine #1126).
move fuller example from notes to example section
Merge pull request #243 from cf-gary/master

move fuller example link for namespaces
introduce (body executor control).agent_expireafter
function to check and time out on file descriptors not ready for reading
utility to convert pipe to pid of connected process
unix utilities to signal process termination sequence and check existence
terminate expired agents in cf-execd
Update ChangeLog.
print promise handle in duplicate error message
Acceptance tests for basic client-server copy
Define basic server settings for acceptance tests
Index for the tests
Add a test